I don't have any experience of the Pearl but I've been running a Monarch 4.2 for the past 2 months and so far I'm pleased with it. It perform well on most terrain types and there's more than enough tuning with the floodgate and rebound adjusters. The floodgate on/off switch is handy for reducing bob when climbing although it's not a full lockout facility. It's too early to tell how reliable it is so can't comment on that.

I've got a basic Pearl 3.1 on my prophet it's ok has been reliable, been on their for over 20 months and not been touched apart from changing/checking air but if I was buying new i'd go for a Fox rp23.